Final answer:
The relationship between exercise and the reduction of mental illness symptoms is directly proportional, meaning increased exercise typically corresponds to decreased mental health issues.
Step-by-step explanation:
The relationship between the reduction of mental illness symptoms and exercise can be best described as directly proportional. This means that as the amount of exercise increases, there tends to be a corresponding reduction in the symptoms of mental illness. A directly proportional relationship implies that if one variable goes up, the other one also goes up. This concept aligns with evidence that physical exercise contributes to reduced stress, improved body image, and enhanced self-esteem. Conversely, a sedentary lifestyle is often associated with an increased risk of developing anxiety, indicating that more exercise typically leads to better mental health outcomes.
To clarify, an inverse proportionality would mean that one variable goes up while the other goes down, which is not the case here. As for an exponential relationship, it describes a situation where the rate of change itself increases as the dependent variable grows, which is more common in scenarios like population growth, but not typically in the relationship between exercise and mental health. Therefore, the answer is (b) directly proportional.